classix

classix

The fastest and tiniest utility for conditionally joining classNames.

Installation

npm install classix

Usage

Use any amount of string expressions and classix will join them like so:

import cx from "classix";
// or
import { cx } from "classix";

cx("class1", "class2");
// => "class1 class2"

cx("class1 class2", "class3", "class4 class5");
// => "class1 class2 class3 class4 class5"

cx("class1", true && "class2");
// => "class1 class2"

cx(false && "class1", "class2");
// => "class2"

cx(true ? "class1" : "class2");
// => "class1"

cx("class1", false ? "class2" : "class3");
// => "class1 class3"

cx(...["class1", "class2", "class3"]);
// => class1 class2 class3

cx(
  "flex",
  isPrimary ? "bg-primary-100" : "bg-secondary-100",
  isLarge ? "m-4 p-4" : "m-2 py-2"
);
// => "flex bg-primary-100 m-2 p-2" *assuming isPrimary is true and isLarge is false

Comparison

	classix	clsx	classnames
Size	281B	330B	454B
Ops/s*	29M	28M	7M
Strings	Yes	Yes	Yes
Numbers	Yes	Yes	Yes
Booleans	Yes	Yes	Yes
Arrays	Yes with spreading	Yes	Yes
Objects	No**	Yes	Yes

*Operations per second on an AMD Ryzen 5 5600x

**classix aims to provide the fastest and tiniest utility by omitting the object API, which it considers less ergonomic than standard function arguments:

// 🚫
cx({ class1: isPrimary && isLarge, class2: !isPrimary || !isLarge });
// ✅
cx(isPrimary && isLarge ? "class1" : "class2");

Highlights

• Fastest & tiniest
• Zero dependencies
• Fully typed (with TypeScript)
• Fully tested
• Follows semantic versioning

Changelog

For a list of changes and releases, see the changelog.

Contributing

Found a bug, have a question or looking to improve classix? Open an issue, start a discussion or submit a PR!